Sector gates for spillway in (U.S.A.)

Abstract

The spillway of the Wanapum dam, on the Columbia (U. S. A.), includes 12 sector gates, designed by the Harza Engineering Company Each gate closes an opening of 15 x 20 m. The hinges of the gates are supported by reinforced concrete blocks, suitably anchored on the top side of the dam, by means of 14 cables, each made up of 90 wires of 6.35 mm diameter. This avoids the use of heavy metal structures, normally necessary to withstand the thrust of the gates. The anchorage blocks and the main supporting piles contain grooves, into which the gate hinges, one on each side of each anchorage block, are located. The determination of the three dimensional stress distribution in these anchorage blocks was carried out on reduced scale models, in which aluminium was used. Other models were studied by photoelastic methods. These analyses enabled to decide the best shape and internal distributed of the reinforcement. The disparity between the results obtained on the aluminium models and in the photoelasticity investigations were negligeable.